The Collaborative International Dictionary of English v.0.48:

Potluck \Pot"luck`\, n.
   Whatever may chance to be in the pot, or may be provided for
   a meal.
   [1913 Webster]

         A woman whose potluck was always to be relied on. --G.
                                                  Eliot.
   [1913 Webster]

   To take potluck, to take what food may chance to be
      provided.
      [1913 Webster]